Oxo-bottoms base lubricating grease



Patented Sept. 22, 1953 OXO-BOTTOMS BASE LUBRICATING GREASE Arnold J. Morway, 'Jr.,.Westfield, N.

Development Company,

' ware No Drawing.

14 Claims.

This invention relates to an improved lubricat ing composition and particularly to a lubricating grease employing a synthetic oil as the soap dispersant. More particularly it relates to an improved lubricating grease made by dispersing a lithium soap in a synthetic oil.

The synthetic oils which are used as the dispersant for the lithium base soaps in the formulation of the greases of this invention are obtained from the so-called OX0 process. This process may be described as the catalytic reaction of mono-olefins with carbon monoxide and hydrogen at a temperature of about 300 F. to 350 F. and under a pressure of about 3000 pounds per square inch to form an aldehyde. This aldehyde is then hydrogenated to form a primary alcohol. The process was developed in Germany and was first described in this country in U. S. Patent 2,327,066, issued to Roelen in 1943. Depending upon the starting olefin, various alcohols may be synthesized by this process. For example, a (3'! fraction isolated from the" polymerization product of propylene or a mixture of C3 and C4 olefins, may be subjected to the Oxo process. The resulting oxo-alcohollmixture will be found to have a majorproportion of Ca alcohol isomers having on the average two 'alkyl side groups along a carbon chain 6 carbon atoms in length. Other higher molecular weight compounds are also present. 7

From this reaction product, which contains a major proportion of Ca Oxo-alcohol, thedesirecl cuts are removed by distillation. For example the C8 OXo-alcohols are removed by distillation and the bottoms or residuum left from the distillation contains a large proportion of C9 OX0- alcohols, higher boiling alcohols, acetals, esters, ethers, and hydrocarbons. In a second distillation the C9 Oxo-alcohols and any other low boiling material, that is, materials boiling below about 250 C., may be removed. The residuum left from this second distillation, or topping, represents approximately 33% to 35% of the residue remaining after the Ca Oxo-alcohols are removed. 7 v

I Although higher boiling materials obtained by Rahway, and Paul V. Smith, J assignors to Standard Oil a corporation of Dela- Application December 17, 1949, Serial No. 133,664

2 residuum boiling above about 250 C. When employing greases where some slight volatility is immaterial, a still greater proportion of the total product may be used, that portion boiling above about 210 C., for instance.

Although the above description is specifically directed to an Oxo process for the production of a major amount of Ca Oxo-alcohol, and the preferred embodiment of this invention contemplates the use of the bottoms from this particular process, the invention is not limited to the use of these particular bottoms. The synthetic oils or the residue remaining after distillation of the mixture of products obtained by subjecting a wide variety of olefins to the 0x0 process are operable. For instance, any of the various olefins obtained by polymerizing mixtures of propylenes and 'butylenes may be subjected to the Oxo process and the bottoms from these processes may be used. In addition, the olefins obtained from the hydrocarbon synthesis reactions may be converted to Oxo alcohols and other products and these bottoms are operable in this invention. Inthe preferred embodiment that portion of the product of the Oxo process remaining after the C8 Oxo-alcohol cut and the C9 Oxo-alcohol out are removed, that is to say, that portion remaining after the product has beensubjected to a temperature of 250 C., are hereinafter referred to as "Oxo bottoms. The approximate composition of the residuum boiling above 250 C. is as follows:

Inspection tests on this residuum show:

alcohols Flash point over 350 F. Pour point 55 E Viscosity:

100.F 68.3 S. U. S. 2'10 F. 34.9 S. U. S.

a removal of still greaterproportionsof low boiling materials, that 280 C., are operable greases, it is preferred to use that portion'of the is, by distillation to about for the manufacture of these 7 I These Oxobottoms may be utilized directly as the synthetic oil used in the manufacture of the grease compositions of this invention if desired.

However; it is also within the concept of this invention to esterify any of the saturated dibasic acids with these Oxo bottoms and use the resulting product as the soap dispersant. Although a wide range of the saturated dibasic acids are operable in this particular concept, it is preferred to use the dibasic acids having from 4 to 12 carbon atoms, among which are adipic and sebacic acid.

Among the soap constituent operable in formulating the greases of this invention are any of the lithium soaps of the long chain high molecular weight substantially saturated fatty acids or other materials commonly in use in grease making. A partial list of those materials would inelude hydrogenated fish oil acids, stearic acid, oleic acid, hydroxy stearic acid, beef fat, lard oil, tallow, the saturated or unsaturated glycerides of various fatty acids, or mixtures of the above in any proportion. The preferred embodiment for the lithium base grease of the instant invention utilizes the lithium soap of hydroxy stearic acid.

The novel greases of this invention preferably contain from to 15% by weight of the lithium soap combined with about 85% to 90% by weight of the Oxo bottoms. Operable greases may be made, however, with from about 5% to of the soap with from about 80% to 95% of the synthetic oil.

It is also within the concept of this invention to prepare a grease composition employing an aluminum soap of a high molecular weight substantially saturated fatty acid. In this instance,

however, it is desirable to incorporate with thesynthetic oil a major amount of a mineral oil, since dispersion of the aluminum soap in the synthetic oil alone fails to give a satisfactory grease structure. For optimum results the mineral oil, the synthetic oil and the aluminum soap in powdered form are slurried together, heated to the desired temperature, and then cooled to room temperature.

The novel lubricating compositions of this invention. are exemplified by the following:

EXAMPLE I Formulation worker employing the fine hole worker plate (325 1 g" diameter Smooth, buttery.

holes)) at 77 F.) 306 m l/1f). Water solu ility Insoluble in boiling 1 water. Bearing test No t e n d e n c y to become fibrous and heterogeneous in o p e ration in an anti-friction hearing at 250 F.

Dropping point (F.) 332.

t will be noted that this grease composition has excellent structural stability having an uning the AN-G-25' specification for worked penetration of 275 mm./10 and losing only 31 mm./l0 in hardness after 100,000 strokes in the ASTM worker. Its insolubility in water and its high dropping point make it especially adaptable in some operations.

EXAMPLE II Formulation 6.0% lithium stearate 6.0% lithium hydroxy stearate 87.0% Oxo bottoms (boiling above 250 C.) 1.0% phenyl alpha naphthylamine Procedure Same as in Example I.

Tests run upon this grease composition gave the following results:

Appearance Structural stability:

Penetration, unworked Penetration, after working for 50,000 strokes in the ASTM worker with the fine hole plate (at 77 F.)

Smooth, buttery.

280 mm./l0.

Water solubility Insoluble in boiling Water. Bearing test No tendency to become fibrous up to 250 C. Dropping test (F.) 348.

13.0% lithium hydroxy stearate 86.0% Oxo bottoms (boiling above 250 C.)

1.0 amine type oxidation inhibitor (commercially known as PSF-34 manufactured by Du Pont de Nemours Co.)

Procedure Same as in Example I.

Routine tests run on this grease composition ave the following results:

Appearance Smooth but Structural stability Penetration, tery unworked 273 mm./l0.

Structural stability to mechanical working: Penetration (after work mg 100,000 strokes in the ASTM worker employing the fine hole worker plate (at 77 F.)

Water solubility Bearing test Insoluble in boiling water.

No tendency to become fibrous and heterogeneous in operation in an 1nti-cri2c5t(i)on bear- Dropping point (F.) 330 F The grease composition of Example III was subjected to the Norma-Hoffman bomb oxidation test and gave excellent results. In this test, operating at 210 F. and 110 pounds per square inch initial oxygen pressure, the pressure dropped only 5 pounds per square inch in over hours. This result meets the stringent resistance to oxidation requirements of most government specifications, the most pertinent below temperature aeronautical grease.

This grease composition also gave excellent results in the standard corrosion test. In this test a polished strip of copper was immersed in a sample of the grease and maintained at a temperature of 210 F. for 24 hours; After the test the strip gave no sign of pitting or staining, and was identical in color and brightness a er the est th he e ra s r It will be noted that the above examples utilize the Oxo bottoms themselves as the synthetic oils for the soap dispersants. As was mentioned above, very satisfactory grease compositions may be made by first esterifying the 0x0 bottoms with a saturated dibasic acid and using the resulting ester mixture as the dispersant.

When the 0x0 bottoms are used by themselves as the synthetic oil they are topped, that is, the material after the Ca Oxo-alcohol cutv is removed is subjected to a second distillation at about 250 F. to remove the C9 Oxo-alcohols and the lower boiling constituents. The resulting bottoms, as was described above, constitutes approximately 30% of the total bottoms out. When it is desired to first form the esters from these Oxo bottoms, and use the resulting ester mixture as the soap dispersant, the total product remaining after the C8 Oxo-alcohols are distilled off is used. That is to say, the desired saturated dibasic acid is reacted with a material obtained when a monolefin is subjected to the 0x0 process which boils above. about 210 C. Normally, a preformed soap is dispersed in the synthetic oil. However it may be desirable to form the soap in situ and in order to prevent the hydrolysis of the mixture of esters it may be desirable to employ a mineral oil. In this mineral oil, in proportions which may vary widely, depending upon the constituents used, the desired soap is formed and the synthetic oil then added.

Examples of the grease structures so prepared are given below.

EXAMPLE IV Formulation 6.0 lithium stearate (preformed) 6.0 lithium hydroxy stearate 87.0% adipic ester of 0x0 bottoms 1.0% phenyl alpha naphthylamine Procedure The combined soaps were dispersed in the esterified bottoms by heating to 400 F. and cooled by pouring the hot molten grease into pans. The cold grease was then homogenized by working to a smooth, uniform mass in a grease kettle.

Properties Appearance Smooth, uniform buttery structure. Dropping point F.) 365. Penetration, unworked 275 mm./l0. Penetration after 100,000 strokes 322 mm./10.

employing a fine hole worker plate. Water solubility in boiling H20- Insoluble. Bearing test Nofhange in structure of the grease a I 250 Aeration (beating 1 hour at 77 F.) None.

EXAMPLE V Formulation lithium stearate (preformed) 85 sebacic ester of Oxo bottoms orperating temperature of 100,000 strokes in the ASTM worker employing a fine hole worker plate. Water solubility in boil ng H2O None.

(1 hour). Bearing test--.-- ..'No change in grease structure t operating temperatures of 250 F.

6 A comparison of the properties of these Oxo bottom esters with the esters of pure C8 alcohol (Z-ethylhexyl) and pure Ca Oxo-alcohol are shown below:

The grease composition of Example V was subjected to the Norma-Hoffman bomb oxidation test and gave excellent results. Operating at 210 F. and 110 pounds per square inch initial oxygen pressure, the pressure drop was only 5 pounds per square inch in 150 hours. This grease composition also successfully passed the copper strip corrosion test showing no corrosive properties whatsoever.

The grease composition of Example V was subjected to a low temperature torque test as prescribed by the Army-Navy aeronautical specification ANG-25. In this test a 204K Conrad type eight-ball bearing, in a cold box capable of holding the temperature variation of the bearing during the test to not more than :1.8 F., was packed with 3 grams of the grease. The packed bearing was inserted in the cold box and the temperature lowered to 67 F. Following the procedure detailed in the AN-G-25 specification on page 7, the results of the test were as follows:

One revolution of the bearing occurred in 9.0 seconds and 9.4 seconds in duplicate runs.

The grease compositions of this invention may include any of the conventional additive materials known to the art such as tackiness agents, viscosity index improvers, anti-corrosion agents, oxidation inhibitors, extreme pressure agents and the like. 7

Although the grease compositions of this invention are primarily concerned with a lithium soap dispersed in a synthetic oil, it is also within the inventive concept to use mixtures of the synthetic oils described above and the natural occurring mineral base oils. The proportions of V the two types of oils may vary within wide limits depending upon the final grease composition desired. The use of mixtures of the synthetic oils and the mineral base oils is particularly desirable when aluminum soap grease is desired and the use of a minor proportion of a natural mineral base oil is desirable to prevent hydrolysis of the esterified Oxo bottoms when the dispersant used is the dibasic acid esters of the 0x0 bottoms.

' What is claimed is:

1. A new and improved grease composition which comprises a synthetic oil thickened to a grease consistency with from about 5.0% to 20.0% by weight of the lithium soap of a high molecular weight substantially saturated fatty acid, said synthetic oil bein the residue of distillation at a temperature of about 210 C. of the mixture of products obtained by subjecting a mono-olefin to the action of carbon monoxide and hydrogen in the presence of a cobalt catalyst at a temperature of about300 F. to 350 F. and under a pressure of about 3000 pounds per square inch which has been hydrogenated to a predominately primary alcohol mixture containing one more carbon atom than themonoolefin.

2. A lubricating composition according to claim 1 wherein the lithium soap is lithium stearate.

3. A lubricating composition according to claim 1 wherein the lithium soap is lithium hydroxy stearate.

4. A lubricating composition according to claim 1 wherein from 10% to 15% by weight of said lithium soap is dispersed in from 85% to 90% by weight of said synthetic oil.

5. A new and useful lubricating composition which comprises about 5.0% to 20.0% by weight of a lithium soap dispersed in a synthetic oil base; said synthetic oil base being formed by esterifying the residue remaining after distillation at about 210 C. of the mixture of products obtained by subjecting a mono-olefin to the action of carbon monoxide and hydrogen in the presence of a cobalt catalyst at a temperature of about 300 F. to 350 F. and under a pressure of about 3000 pounds per square inch which has been hydrogenated to a predominately primary alcohol mixture containing one more carbon atom than the mono-olefin, with a saturated dicarboxylic acid containing from 4 to 12 carbon atoms.

6. A lubricating composition according to claim 5 wherein the synthetic oil dispersant is the x0 alcohol bottoms ester of adipic acid.

7. A lubricating composition according to claim wherein the synthetic oil dispersant is the Oxo alcohol bottoms ester of sebacic acid.

8. A lubricating composition according to claim 5 wherein from to by weight of said lithium soap is dispersed in from 85% to 90% by Weight of said synthetic oil.

9. A new lubricating composition which comprises about 5.0% to 0.0% by weight of a lithium soap dispersed in a synthetic oil base, said synthetic oil being the residue remaining after distillation at about 250 C. of the mixture of products obtained by subjecting a mono-olefin to the action of carbon monoxide and hydrogen in the presence of a cobalt catalyst at a temperature of about 300 F. to 350 F. and under a pressure of about 3000 pounds per square inch which has been hydrogenated to a predominately primary alcohol mixture containing one more carbon atom than the mono-olefin.

10. A lubricating composition according to claim 9 wherein the lithium soap is lithium stearate.

11. A lubricating composition according to claim 9 wherein the lithium soap is lithium hydroxy stearate.

12. A lubricating composition which comprises about 15% by weight of lithium hydroxy stearate dispersed in about 85% by weight of a synthetic oil, said oil being the distillation residue remaining when the product of the 0x0 process is subjected to distillation at about 250 C. and comprising approximately 85% of a mixture C12 0x0- alcohols and higher Oxo-alcohols, 5% C13-] acetals, 5% C14+ esters of mixed alcohols and acids, and 5% of a mixture of high molecular weight ethers and hydrocarbons.

13. A lubricating composition which comprises a mixture of a minor but stabilizing amount of a naturally occurring mineral oil and a major amount of a synthetic oil, said mixture being thickened to a grease consistency with about 5.0 to 20.0% by weight of a lithium soap of a high molecular weight substantially saturated fatty acid, said synthetic oil being the residue of distillation at a temperature of about 250 C. of the mixture of products obtained by subjecting a mono-olefin to the action of carbon monoxide and hydrogen in the presence of a cobalt catalyst at atemperature of about 300 F. to 350 F. and

under a'pressure of about 3000 pounds per square inch which has been hydrogenated to a predominately primary alcohol mixture containing one more'carbon atom than the mono-olefin.

14. A lubricating composition which comprises a synthetic oil thickened to a grease consistency with about 2.0% to 20.0% by weight of the lithium soap of a high molecular weight substantially saturated fatty acid, said synthetic oil being selected from the class consisting of the 210 C. and the 250 C. distillation residues of the reaction product of a mono-olefin with carbon monoxide and hydrogen in the presence of a cobalt catalyst at a-temperature of about 300 F. to 350 F. and under a pressure of about 3000 pounds per square inch'which has been hydrogenated to a predominately primary alcohol mixture containing one more carbon atom than the mono-olefin, and the C4 to C12 saturated dibasic acid esters thereof.

ARNOLD J. MORWAY. PAUL V. SMITH, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,436,347 Zimmer et al Feb. 1'7, 1948 2,450,221 Ashburn et a1 Sept. 28, 1948 2,491,028 Beerbower et al. Dec. 13, 1949 2,491,054 Morway Dec. 13, 194 2,497,133 Morway et a1 Feb. 14, 1950 2,516,137 Morwayet al. July 25, 1950 2,594,341 Owen et al. Apr. 29, 195 2,595,096 Parker Apr. 29, 1952 OTHER REFERENCES Wonder and Orchin: Critical Review of Chem. of Oxo-Synthesis, Bur. of Mines, R. I. 4270; June 1948; 260-59'7A; pp. 6 and 9.

Hain et al.: Synthetic Low Temperature Greases from Aliphatic D-iesters, Article in Ind. 2121; Chem., vol. 39, April 1947, pp. 500-506; 

1. A NEW AND IMPROVED GREASE COMPOSITION WHICH COMPRISES A SYNTHETIC OIL THICKENED TO A GREASE CONSISTENCY WITH FROM ABOUT 5.0% TO 20.0% BY WEIGHT OF THE LITHIUM SOAP OF A HIGH MOLECULAR WEIGHT SUBSTANTIALLY SATURATED FATTY ACID, SAID SYNTHETIC OIL BEING THE RESIDUE OF DISTILLATION AT A TEMPERATURE OF ABOUT 210* C. OF THE MIXTURE OF PRODUCTS OBTAINED BY SUBJECTING A MONO-OLEFIN TO THE ACTION OF CARBON MONOXIDE AND HYDROGEN IN THE PRESENCE OF A COBALT CATALYST AT A TEMPERATURE OF ABOUT 300* F. TO 350* F. AND UNDER A PRESSURE OF ABOUT 3000 POUNDS PER SQUARE INCH WHICH HAS BEEN HYDROGENATED TO A PREDOMINATELY PRIMARY ALCOHOL MIXTURE CONTAINING ONE MORE CARBON ATOM THAN THE MONOOLEFIN. 